Hello Alan,
Thanks for your query. I understand that you want to notify a group of people using Email notifications when any edit is made to your Google Sheets. We can accomplish this using an Apps Script code and setting a Google Sheets On Edit trigger.
Consider the following spreadsheet with multiple worksheets. To enter the Apps Script code in this spreadsheet, click the Extensions tab and select the Apps Script command.

As a result, a new tab like the following will appear in your browser.

Enter a project name >> replace the default function with the following code >> click the Save button >> click the Trigger command from the left-side pane.

function onEdit(e){
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var ws =ss.getActiveSheet();

  var range = e.range;
  var oldValue = e.oldValue;
  var newValue = ss.getActiveCell().getValue();

  if (oldValue === "" && newValue === ""){
    return;
  }

  if (oldValue === newValue){
    return;
  }

  var cellAddress = ws.getActiveCell().getA1Notation();
  var editor = Session.getActiveUser().getEmail();
 
  var recipient = "[email protected], [email protected]";
  var sub = "Cell Modification";
  var body = "Modified Spreadsheet: " + ss.getName() + "\nModified Sheet: "+ ws.getSheetName() + "\nEdited Cell: " + cellAddress + "\nEdited by: " + editor + "\nPrevious Value: " + oldValue + "\nCurrent Value: "+ newValue;

  MailApp.sendEmail(
    recipient,
    sub,
    body
  );
}

Consequently, you will get the Trigger options. Click on the Add Trigger button.

This will open the Add Trigger dialog box. Set the Choose which function to run option to OnEdit (i.e. your current function) >> set the Select the event source option to From spreadsheet >> set the Select event type option to On edit >> set the Failure notification settings option to Notify me immediately >> click the Save button.

Click the Editor command from the left-side pane and then click the Run button from the editor.

Note:
1) When you run the code for the first time, you must review permissions for authorizing Google Sheets to use your Google Account to run this script.
2) You may get an error message when you run the above code. This is normal as you have run the script but no change hasn’t occurred to your spreadsheet. When any change occurs in your spreadsheet, this script will run automatically from now on.
Now, make any changes to your spreadsheet. In the Research Data worksheet, I have changed Cell F7’s value from Planning to Completed.

As a result, each person whose email address was included in the Apps Script code will receive an email like the following:

And that’s how you can send email notifications to multiple people for any edit in your worksheet. Let us know your feedback on the solution. The Google Sheets used for this solution is linked below:
Google Sheets Notify Multiple Users Using Apps Script

Regards,
Seemanto Saha
OfficeWheel